Unitary cordless dental drive apparatus

ABSTRACT

The invention provides a unitary cordless dental drive apparatus with a cantilever arm extending outward and positioned to allow a dental nose cone to be connected. An activating switch is located at the free end of the cantilever arm in a position that is convenient for manipulation by a user. In a second embodiment, the switch is in the form of a contactor mounted below the cantilever arm to contact the nose cone when pressed. In a third embodiment, a foot pedal connected to a wireless transmitter is provided to send a signal to a receiver located within the handpiece for activating the handpiece.

RELATED APPLICATION

This application is a conversion and retains priority of provisionalpatent application No. 62/298,493 filed Feb. 23, 2016.

FIELD OF THE INVENTION

The present invention relates to the field of dental equipment, and moreparticularly to a dental cordless drive apparatus incorporating arechargeable battery power source and a cantilevered activating switch.

BACKGROUND OF THE INVENTION

The practice of dentistry utilizes a plurality of power driven tools forremediating decayed dental areas and for cleaning tooth surfaces.Traditional dental equipment is driven by an external drive device tocause the tool to rotate. The external drive device may be either amotor with an articulable power transmission, e.g. a pivoting pulley andbelt system, a supply of compressed air that is directed to the dentalhandpiece through tubing, or an electric motor in the dental handpiecethat is powered by an electrical cord. These three drive systems providethe needed power, but the connected hoses, pulleys and belts, orelectrical cords cause them to be fairly cumbersome and fatiguing touse, particularly for extended periods of time, as is typically the casein professional cleaning of a patient's teeth.

Recent developments in dental equipment have provided certain advancesin apparatus for the rotating of dental tools. These drive devices aresubstantially self-contained and free of a cumbersome external drive.These devices have a battery and a motor within the handpiece, therebyeliminating the cumbersome power transmission apparatus. The resultantcordless handpiece is more easily manipulated and, especially in use bya dentist or dental hygienist for long periods during dental cleanings,less likely to cause fatigue. However, the known devices are limited inthe manner for controlling the power, i.e. switched on and off. Theknown cordless handpieces are controlled by a switch that is located inan inconvenient position. The switch on known devices is located eithertoward the rear of the handpiece or near the front of the handpiece. Thedental hygienist must hold the handpiece with one hand and actuate theswitch with the other hand, typically done before the dental tool is inthe patient's mouth. When used for cleaning the patient's teeth, thisresults in much of the cleansing paste being sprayed outside of themouth, which tends to be wasteful and messy. In addition, tooth cleaningis typically done with a series of short bursts of drive power, makingthe remotely located switch even more inconvenient. In order to rotatethe dental tool at the forward end of the handpiece, the entirehandpiece must be rotated. The present invention provides a unitarycordless dental drive apparatus that is an improvement on, and overcomesthe drawbacks of, the known prior devices.

SUMMARY OF THE INVENTION

The invention disclosed below provides a unitary cordless dental driveapparatus adapted for flexible, comfortable, and durable dental officeservice. The novel handpiece has a battery power source, a drive motorand a gear train enclosed in a housing. The housing is split to enableopening for factory servicing. A European type (E-type) output shaftextends from the gear train, allowing all universal dental nose conesand tools to be connected. The battery power is connected to the motorthrough a switch which, in the first preferred embodiment, is supportedat the free end of a cantilever arm and located in a position to beconvenient for the user. The invention includes a microprocessor, orprogrammable logic control, enabling a variety of functions for theswitch, e.g. on/off, momentary contact, timed cycle on with automaticoff, varying operating speed by steps each time the switch is pressed.The cantilever arm may be internally reinforced by a resilient wire. Ina second embodiment of the invention, a cantilever arm is incorporatedwith an electrically conductive contactor, the arm adapted for flexingunder pressure to cause the contactor to touch a conductive part of thedental nose cone to activate the drive motor. In a third embodiment ofthe invention, a wireless receiver is included within the dentalhandpiece. A wireless transmitter is mounted to an output of pressurizedair from a standard dental foot pedal. The dental handpiece of thepresent invention is wirelessly activated and controlled for speed bythe application of pressure on the standard existing dental foot pedal,causing the wireless transmitter to send a signal to the wirelessreceiver. The wireless receiver is directly in control of the handpiecemotor. In all embodiments of the invention, the dental handpiece isfully operable with no directly connected air hoses or drive belts andpulleys.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is best understood in conjunction with theaccompanying drawing figures in which like elements are identified bysimilar reference numerals and wherein:

FIG. 1 is a side elevation view of the unitary cordless dental driveapparatus in a first embodiment.

FIG. 2 is a side elevation view of the unitary cordless dental driveapparatus in a second embodiment.

FIG. 3 is an exploded side elevation view of the embodiment of FIG. 1with the dental handpiece illustrated in cross section.

FIGS. 4A and 4B are side elevation views of the cordless drive apparatusbeing placed into a charging base and set into the charging base.

FIG. 5 is a schematic view of a third embodiment of the invention inwhich power is controlled by an existing dental foot-operated pedal andsent wirelessly from a transmitter to a receiver in the dentalhandpiece.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a first embodiment of the present invention isshown in side elevation view. The unitary cordless dental driveapparatus is designated handpiece 10. Handpiece 10 includes a power unit12, e.g. a rechargeable battery, a power converter unit including amotor and a gear train. The internal components of handpiece 10 arepreferably encased in a sealed housing for protection against moistureand contamination. A conventional dental nose cone 26 is removablymounted to handpiece 10. Nose cone 26 receives power from power unit 12to rotatably drive a prophylaxis angle device 28. It will be understoodthat the present invention may be beneficially utilized withnon-disposable prophylaxis angle devices as well as disposable ones.Depending on the purpose for which the present invention is to be used,another dental attachment may be employed, e.g. an abrasive tip. Aswitch 20 is mounted to the free end of an arm 18, arm 18 being fixedlyassembled in cantilever fashion to the housing portion of handpiece 10to position switch 20 conveniently for being contacted by a user'sfingertip F when in use. Arm 18 is configured as a cantilever structureto suspend switch 20 and maintain a space between arm 18 and nose cone26, permitting nose cone 26 to be readily mounted and removed. Switch 20is preferably in the form of a micro-miniature membrane switch that isconnected to a microprocessor (not shown) within handpiece 10, themicroprocessor including a transistor relay activated by switch 20. Whenactivated, the transistor relay connects the enclosed battery powersource to the motor, causing the cleansing paste cup of prophylaxisangle device 28 to rotate. Switch 20 also activates an indicator 16,e.g. a miniature LED light source. Indicator 16 may be programmed toremain continuously on, flash on in a specified pattern, as well asdisplay different colors for different conditions, e.g. normaloperation, excessive power being drawn from the power source, or thepower source in need of recharging, etc. As will be understood by thoseskilled in the trade, the location of switch 20 at the free end ofcantilever arm 18 allows the dental hygienist to place the tip ofprophylaxis angle device 28 inside the mouth of the patient beforeactivating power unit 12, thereby avoiding spraying and waste of thecleansing paste.

Referring now to FIG. 2, a second embodiment of the present invention isshown in side elevation view. Handpiece 10′, power unit 12′, nose cone26′, and prophylaxis angle device 28′, are substantially similar tocomparable components in the first embodiment shown in FIG. 1. Acantilever arm 18′ extends outwardly from handpiece 10′. The secondembodiment of FIG. 2 differs from the first embodiment of FIG. 1 in thatthe electrical circuit is completed by a contactor 22 mounted to thelower surface of arm 18′. As nose cone 26′ is typically metallic, whenthe user presses arm 18′ to flex downward with fingertip F to causecontactor 22 to touch nose cone 26′, a circuit is closed between thebattery and the motor. As will be described below, cantilever arm 18′ ofthis second embodiment is designed to be flexed by finger pressure. Thissecond embodiment of the invention also incorporates the primaryobjective of locating contactor 22 for convenient use by the dentalhygienist during tooth cleaning or other functions.

Referring now to FIG. 3, the unitary cordless dental drive apparatus ofthe first embodiment is shown with the components arrayed in explodedside elevation view. The components are in position to be assembledalong axis A, shown as a dashed line. Handpiece 10 is shown in crosssection for clarity. Handpiece 10 has a unitary housing 14 withcantilever arm 18 molded integrally therewith. Arm 18 may, optionally,be reinforced to withstand flexural stress with the incorporation of oneor more reinforcing rods 24, e.g. piano wire. Indicator 16 is alsomolded into arm 18 and incorporated in the electrical circuit ofhandpiece 10. Electrical power is provided by a battery 34 to a motor 46which is mechanically coupled to a gear train 48 for driving an outputshaft 50 at a selected rotary speed and torque. Battery 34 may be eithera rechargeable or non-rechargeable replaceable type. Gear train 48 maybe configured to provide continuous rotary action or reciprocatingrotary action according to the intent of the manufacturer. Output shaft50 with coupler 54 and nose cone 26 are in the configuration known inthe trade as an E-type coupling to connect securely to one another. Inthe preferred embodiment of the invention, coupler 54 is sized to fitslidingly into nose cone 26, allowing the user to swivel nose cone 26and prophylaxis angle device 28 while keeping handpiece 10 upright withswitch 20 at the fingertip position. Prophylaxis angle device 28 ismounted to nose cone 26 and driven through nose cone 26 by shaft 50.Battery 34 is preferably a rechargeable battery with an operating ratingof 650 milliampere hours at 3.7 volts. Handpiece 10 includes a chargingconnector 36 that is configured to operatively engage a charging basedevice when battery 34 is in need of being recharged.

Referring further to FIG. 3, arm 18 extends outwardly from handpiece 10in cantilever fashion to position switch 20 suspended at a convenientplacement for being manipulated by finger pressure of the user. In thepreferred embodiments of the invention, housing 14 of handpiece 10 isformed of a light weight material, e.g. high density polyethylene.Whereas the plastic encased handpiece is not receptive to repeatedautoclaving, and whereas only the nose cone 26 and prophylaxis angledevice 28 contact the mouth of the patient, it is not generallynecessary to autoclave handpiece 10. Handpiece 10 may be adequatelyprotected by applying a thin sleeve over the handpiece prior to theprophylactic procedure and/or cleaning by use of a disinfectingsolution. The dental tool, specifically the disposable prophylaxis angledevice 28, is discarded after use. In the first embodiment of theinvention, metallic reinforcing bars 24, shown within cantilever arm 18,are sized to maintain the structural rigidity of arm 18 against fingerpressure on switch 20. Reinforcing bars 24 also serve to conductelectrical current from power source battery 34 through switch 20 tomotor 46. It is understood in the second embodiment of the invention(see FIG. 2) that reinforcing rods 24 shown in FIG. 3 in arm 18 aresized to be resilient and spring back to the original shape. Theplacement of switch 20 on cantilever arm 18 allows nose cone 26 or otherdental attachments to be assembled and removed from coupler 54 whilelocating switch 20 for comfortable use by the dental hygienist.

The unitary cordless dental drive apparatus of the invention is for useby dentists and dental hygienists, some of whom may apply excessiveforce of the cleaning cup of the prophylaxis angle device against thepatient's teeth. This excessive pressure places a strain on the motor,potentially causing motor damage. Excessive pressure against the teethmay also cause damage to the enamel. To avoid enamel damage and motordamage, an additional feature of the invention is to incorporate anoverload restriction control in the microprocessor that is built intothe handpiece. When an excessive current, e.g. 1.0 amp, is drawn,electrical current is automatically deactivated and a signal isenergized such as light 16 or a buzzer. By deactivating the electricalcurrent and stopping the motor, the dentist or dental hygienist willsoon learn the appropriate degree of pressure to apply.

Referring now to FIG. 4A, a side elevation view is shown of handpiece 10about to be inserted into a recharge unit 56. Recharge unit 56 receiveselectrical power through power cord 60. Recharge unit 56 is formed withan aperture 58 for receiving handpiece 10 slidingly therethrough.

Referring now to FIG. 4B, handpiece 10 is shown as being inserted intorecharge unit 56 for a prescribed period to recharge the battery withinhandpiece 10. While handpiece 10 is illustrated in recharge unit 56without the dental nose cone or dental tool, recharging may beaccomplished equally with or without these components.

Referring now to FIG. 5, a third embodiment of the present invention isshown in schematic side elevation view. In this embodiment, thepreviously described on-board switch has been eliminated from handpiece10 and an existing foot control 64 is employed to activate anddeactivate the motor drive within handpiece 10. The cantilever arm 18″is relatively shorter in this embodiment and includes a signal but noswitch. In the typical dental office application of the invention, footcontrol 64 is connected to receive a supply of pressurized air (notshown). An air hose 68 is connected to an output port of foot control 64to conduct pressurized air to a wireless transmitter 70. The degree ofpressure and flow of air being conducted through foot control 64 totransmitter 70 varies according to the action of the dental hygienist inthe direction indicated by arrow C, the dentist or dental hygienistrepresented by boot D. Transmitter 70 incorporates a pressure sensitiveswitch and any form of wireless transmitter. Transmitter 70 receives thepressurized air and transmits a wireless signal S to a wireless receiver72 that is contained within handpiece 10 and connected internally to themicroprocessor and relay therewithin. As described above, the internalmicroprocessor activates and controls the speed, direction, and durationof action of the dental tool connected to handpiece 10.

While the description above discloses preferred embodiments of thepresent invention, it is contemplated that numerous variations andmodifications of the invention are possible and are considered to bewithin the scope of the claims that follow.

What is claimed is:
 1. A unitary cordless dental drive apparatus,comprising: a. a handpiece having a housing; b. a power source containedwithin the housing; c. an electric motor mechanically connected to agear train, the motor and gear train contained within the housing; d. anoutput shaft connected to the motor and gear train and extending outwardof the housing; e. a hollow coupler formed integrally with the housingin a location to surround the output shaft; f. a foot pedal controlconnected to a supply of pressurized air and having a pressurized airoutput port; g. a wireless transmitter connected to receive pressurizedair through the output port of the foot pedal control to cause thewireless transmitter to transmit a wireless signal in proportion to aflow of air from the foot pedal control; and h. within the handpiece, awireless receiver connected to a relay for conveying power from thepower source to the electric motor; i. wherein when the foot pedalcontrol is pressed, the wireless transmitter sends a wireless signal tothe wireless receiver activating the relay to complete a circuit fromthe power source to the electric motor to activate the electric motor.2. The unitary cordless dental drive apparatus according to claim 1,wherein the power source comprises a battery.
 3. The unitary cordlessdental drive apparatus according to claim 1, wherein the output shaftcomprises an E-type shaft for connecting to an E-type socket within thenose cone.
 4. A unitary cordless dental drive apparatus, comprising: a.a handpiece having a housing; b. a power source and a drive devicecontained within the housing; c. an output shaft connected to the drivedevice and extending outward of the housing; d. a hollow coupler formedintegrally with the housing in a location to surround the output shaft;e. a foot pedal control connected to a supply of pressurized air andhaving a pressurized air output port; f. a wireless transmitterconnected to receive pressurized air through the output port of the footpedal control to cause the wireless transmitter to transmit a wirelesssignal; and g. within the housing, a wireless receiver connected to arelay for conveying power from the power source to the drive device; h.wherein when the foot pedal control is pressed, the wireless transmittersends a wireless signal to the wireless receiver, activating the relayto complete a circuit from the power source to the drive device toactivate the drive device.
 5. The unitary cordless dental driveapparatus according to claim 4, wherein the drive device comprises anelectric motor mechanically connected to a gear train.
 6. The unitarycordless dental drive apparatus according to claim 4, wherein the powersource comprises a battery.
 7. The unitary cordless dental driveapparatus according to claim 4, wherein the output shaft comprises anE-type shaft for connecting to an E-type socket within the nose cone. 8.The unitary cordless dental drive apparatus according to claim 4,wherein the wireless transmitter is responsive to variations in airpressure.